Effect of Gasoline Fuel Additives on Combustion and Engine Performance

Figure 6.13: IMEP for different spark timing, CI-A
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Inte
ns
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y
, 
%
Ignition Timing, CAD BTDC
CI-Additional Base
CI-Additional 1X
9.0
9.2
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9.6
9.8
10.0
10.2
10.4
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IM
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ba
r
Ignition Timing, CAD BTDC
CI-A Base
CI-A 1X
CI-A 10X

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6.3 Engine Testing 
149 
Figure 6.14: IMEP for different spark timing, CI-I
Figure 6.15: IMEP for different spark timing, CI-Additional
of combustion occurring before the power stroke, which would have inherently had an 
effect on the IMEP. Interestingly, the reduction in IMEP between the base fuel and 1X 
concentration of the additive is larger than between 1X and 10X concentrations for all 
but the most advanced sparking point, suggesting a diminishing effectiveness of the 
additive at high treat rates. Figures 6.14 and 6.15 display IMEP for CI-I and CI-
Additional, respectively. In both cases a small decrease in IMEP was experienced for 
majority of the tested range. It is probable this was caused by the radical absorbing 
8.7
8.9
9.1
9.3
9.5
9.7
9.9
10.1
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IM
E
P
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ba
r
Ignition Timing, CAD BTDC
CI-I Base
CI-I 1X
CI-I 10X
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8.9
9.1
9.3
9.5
9.7
9.9
10.1
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